One of the most rapidly growing markets for computer systems is the portable computer market. Recently, portable computers have become more powerful, while also becoming smaller and lighter. Furthermore, as a part of this changing market, the various computer components have become smaller and lighter while their ability to handle more data has increased.
One group of devices which is especially important to portable computers include peripheral input/output devices such as modems, facsimile machines, or local area networks (LANs). A modem, for example, allows a user of a portable computer to correspond with other computers using the telephone lines. A modem provides access to all the data available at the base office without the need to store that data in a portable computer. Consequently, the reduction in size of modems occurred at the same time as the reduction in size of other components, such as hard disks. Typically, electronics for a computer, such as that of a modem, are arranged on an internal board within the computer. Some arrangements provide separate portable electronics which may be carried along and attached to a portable computer when needed. Furthermore, some electronics, modems in particular, have been designed recently which plug into sockets recessed within the body of a portable computer.
Historically, each of the peripheral devices (e.g., modems, facsimile, LANs, etc.) has required its own interface circuitry for connecting to the internal circuitry of a portable computer. This interface circuitry required a separate socket for each device (and thus, required extra space in the internal circuitry of the portable computer). The interface circuitry allowed the peripheral devices to be coupled in order to access the necessary electronics and hardware to provide the device function. For instance, the interface to a modem provides the necessary means for coupling a jack for its operation.
Recently, devices have been devised which allow some of these various forms of computer components to be plugged into the same socket of computer, thereby reducing the space required within the portable computer. For example, an international standard which defines the physical and electrical interface specifications for the interchangeability of memory and input/output cards was introduced by Personal Computer Memory Card International Association (PCMCIA) jointly with the Japanese Electrical Industry Association (JEIDA) in September of 1991. In addition, a specification referred to as an Exchangeable Card Architecture (ExCA) specification, Dec. 20, 1991, has been issued by Intel Corporation of Santa Clara, Calif. The ExCA document describes specifications which manufacturers may use to provide interfaces which are ensured of allowing the memory and input/output cards for portable personal computers of different manufacturers to be interchanged.
A socket design to these specifications allows cards, such as modem and flash memories to be attached, used, and removed interchangeability in the same socket. Computer systems typically include at least one socket recessed within the computer, such that the inserted components (e.g., modem, LAN, etc.) are protected by the body of the computer surrounding the interface circuitry (i.e., socket) in which the components are to be coupled.
The PCMCIA specification provides that the personal computer cards have a sixty-eight pin connector located at the end of the card for the sending and receiving of signals by the card. Currently, the only means of gaining access to signals is through this sixty-eight pin connector. However, only one of the 68 pin placements remains undefined (pin 57). Therefore, only one of the pins may be used to propagate an application specific signal. Many system manufacturers desire to connect critical signals which are not available through the sixty-eight pin connector. Therefore, it is desirable to have access to signals on the personal computer cards other than those which are provided by the standard interface.
Recently, efforts have been made to obtain signals from personal computer cards using external connectors. These external connectors allow for input/output signals to be obtained directly from the card without using its standard interface. For instance, external connectors have been made which connect to integrated circuit cards to obtain access to signals by other than the standard interface (e.g., a PCMCIA standard interface). To implement the external connection, each of the cards contains multiple pins, other than those designated in the 68 pin connector interface, that can be mated with a socket of an external connector. Such connectors are often used to provide signals to jacks, such as Bell Laboratories RJ11 and RJ45 jacks, and other proprietary jacks. Such a connector system is described in co-pending application, Ser. No. 07/782,210, entitled "Integral Connector System for Credit Card Size I/O Card External Connector," filed Oct. 24, 1991, and assigned to the assignee of the present invention. Efforts are currently being taken to create a standard for the external connector type interfaces.
One problem that exists with such an external connector system is that a portable computer user is required to carry all of the external hardware necessary to effectuate the connections. Since the external connection systems employed are dependent on the type of card in use, the portable computer user would be required to carry multiple external connectors to accommodate each of the distinct cards that may be inserted into the computer system. This is often burdensome and increases the overall cost to the system user, since each of the separate external connectors must be purchased. However, signals, and the circuitry responsible for their generation and/or use, other than those provided for by the standard interface (i.e., the 68 pins), are still required to provide the card's functionality. For example, for a modem card to operate, signals still must be provided to a telephone line (i.e., a jack). Thus, it is desirable to eliminate the use of external connectors in conjunction with insertable personal computer cards, yet still be able to obtain signals from the cards by other than their standard interface.